Material Science MCQ Set 5

MATERIAL SCIENCE MCQ SET 5

Q1. Bainite forms at:

A) High temperature
B) Moderate temperature
C) Low temperature
D) Room temperature only

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Answer: B) Moderate temperature
Explanation: Bainite forms at temperatures between pearlite and martensite, offering strength and toughness.

Q2. Which test measures hardness by indentation?

A) Tensile test
B) Charpy test
C) Rockwell test
D) Fatigue test

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Answer: C) Rockwell test
Explanation: Rockwell, Brinell, and Vickers tests measure hardness via indentation.

Q3. The ability of a material to resist fracture under tensile stress is called:

A) Ductility
B) Toughness
C) Strength
D) Hardness

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Answer: C) Strength
Explanation: Tensile strength measures maximum stress a material can withstand before failure.

Q4. Tempered martensite is:

A) Soft and ductile
B) Hard and brittle
C) Soft but brittle
D) Hard but tough

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Answer: D) Hard but tough
Explanation: Tempering reduces brittleness while retaining hardness.

Q5. Ceramic materials typically fail under:

A) Tension
B) Compression
C) Shear
D) Torsion

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Answer: A) Tension
Explanation: Ceramics have high compressive strength but low tensile strength, making them brittle.

Q6. Which of the following is a lightweight metal?

A) Lead
B) Aluminum
C) Iron
D) Copper

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Answer: B) Aluminum
Explanation: Aluminum has low density and is used in aerospace and automotive industries.

Q7. The process used to increase wear resistance of steel surfaces is:

A) Carburization
B) Annealing
C) Normalizing
D) Tempering

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Answer: A) Carburization
Explanation: Carburization introduces carbon into the surface layer, increasing hardness and wear resistance.

Q8. The coordination number of FCC crystal structure is:

A) 6
B) 8
C) 12
D) 4

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Answer: C) 12
Explanation: FCC metals (Cu, Al) have 12 nearest neighbors, giving close packing.

Q9. Which of the following is an example of a refractory material?

A) Glass
B) Clay
C) Alumina (Al₂O₃)
D) Wood

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Answer: C) Alumina (Al₂O₃)
Explanation: Refractories resist high temperatures and are used in furnaces and kilns.

Q10. Which of the following increases the strength of metals?

A) Grain refinement
B) Cold working
C) Solid solution strengthening
D) All of the above

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Answer: D) All of the above
Explanation: Strengthening mechanisms include reducing grain size, plastic deformation, and alloying.